I ran into this this error seemingly randomly. I was able to find a solution in a cached google page MSDN page.
If you encounter this the solution is simple:
1. Build->Build Solution
2. Build->Deploy Solution (or just process what you want)
3. Profit!
Original solution (not reachable for me):
https://social.msdn.microsoft.com/Forums/sqlserver/en-US/268d5c92-5e35-446c-84a6-a1bbe67ea23c/the-xxx-dimension-was-not-found-in-the-xxx-database-on-the-server?forum=sqlanalysisservices
